CBLLULAKINE AND OTHER POLYZOA. 331 
the median row, the rostrum directed obliquely proximally except on the 
distal side of nn ovicell, where the direction is reversed, as in allied species. 
A characteristic feature of Busk's specimen is the occurrence of well- 
developed lateral avicularia on the marginal zooecia. The most interesting- 
point is the presence of basal avicularia, which give off rootlets running on 
the inner side of the lateral avicularia, as shown in Busk's figs. 4, 5. These 
have an acute rostrum, directed proximally, and they are rather longer than 
wide, but not vibracuioid. The spines are well developed, though thin ; 
four occurring on the outer side of the marginal zooecia and two, in addition to 
the scutum, on the inner side. Scutum (PI. 19. fig. 50) with a cavity which 
is very narrow at its commencement but dilates towards the free edge. The 
other zooecia have thi-ee spines on each side, one of them being a scutum on 
one side. In several of the marginal zooecia the distal external spine, which 
is jointed at its base, is enormously elongated, being much longer than a 
zooecium, and running straight distally, just on the outer side of the margin 
of the branch, and parallel with it. The thick walls of these enlarged spines 
appear to be entirely chitinous. The ovicells have a frontal fenestra. 
In addition to the type-slide the British Museum possesses the following 
specimens which I refer to A. nuda : — 
97. 5.1. ■246. Port Phillip Heads, Victoria, J. Bracebridge "Wilson. 
97.5.1.266 and 267. Same locality and donor (labelled Menipea funiculata) . 
97.5.1.250. Port Phillip, Victoria, Miss E. C. Jelly (labelled A. nuda). 
99.7.1.823. Australia, Busk Collection (labelled A. nuda). 
87.12.9.68. Kerguelen, ' Challenger' ( Jollection, Stat. 149 I., 45-127 fathoms. 
Recorded by Busk (1884, p. 19) as Menipea henemunita. 
97.5.1.266 and 267 agree with the type, and differ from the other Victorian 
specimens, by possessing conspicuous marginal avicularia. Some of their 
spines are considerably^ enlarged, notably the second and third marginal ones, 
and the spine on the distal side of the scutum. I have hesitated whether to 
consider them distinct from the other Victorian specimens, but I think it is 
safer to regard them as one species. Basal avicularia are plentiful in all, 
sometimes completely alternate on the two sides of the branch and sometimes,. 
in the same colony, meeting one another in pairs (Pi. 17. fig. 25). The 
branches are at most 5-serial, and the number of spines and the frontal 
avicularia (fig. 21) agree with the corresponding parts of the type. It is 
noteworthy that ovicells occur in all five rows. 
The 'Challenger' specimen from Kerguelen is of more slender habit than 
typical A. henemunita, and is 5-3erial. Its scutum is smaller than in that 
species, and its spines' are 4, 2 -t- scutum, on the marginal zooecia, and 3, S 
(one being a scutum) on the others. In all these respects, as in the characters 
of the marginal and frontal avicularia, it agrees with A. nuda, to which 
I refer it. If my determinations are correct, this species has a circumpolar 
distribution, from Tierra del Fuego to Kerguelen and Victoria. 
